Displaying publications 1 - 20 of 948 in total

Abstract:
Sort:
  1. Fulltext Parametric evaluation of electrical discharge coatings on nickel-titanium shape memory alloy in deionized water
    Mansor AF, Azmi AI, Zain MZM, Jamaluddin R
    Heliyon, 2020 Aug;6(8):e04812.
    PMID: 32913911 DOI: 10.1016/j.heliyon.2020.e04812
    Nickel-titanium shape memory alloy (NiTi) has a unique capacity to restore its initial shape after deformation, which is highly applicable to orthopaedic implantations, especially for the minimization of invasive surgeries. The high nickel content of this alloy can lead to unfavourable effects on the human body upon dissolution; thus, a reliable barrier of coatings on the NiTi surface is required to alleviate the nickel migration and increase its biocompatibility. In this paper, analyses of a titanium oxide layer development on NiTi surface using electrical discharge coating (EDC) process is presented. The recast layer thickness, crater sizes, and surface roughness were characterized based on five parameters; polarity, discharge duration, pulse interval, peak current, and gap voltage. The results show that the discharge duration is the most significant parameter to influence all responses, followed by peak current. The surface characteristics of the EDC substrate is depending on the crater formations and is highly correlated with the discharge energy intensity. As a result, appropriate parametric conditions of the electrical discharge coating process can enhance the NiTi surface for future medical applications, without compromising the shape memory effect.
  2. Fulltext Work place violence (WPV) against healthcare workers in Africa: A systematic review
    Njaka S, Edeogu OC, Oko CC, Goni MD, Nkadi N
    Heliyon, 2020 Sep;6(9):e04800.
    PMID: 32964153 DOI: 10.1016/j.heliyon.2020.e04800
    Background: WPV amongst healthcare workers has been reported as a public health challenge across the countries of the world, with more in the developing countries where condition of care and service is very poor.

    Objectives: We aimed to systematically produce empirical evidence on the WPV against health care workers in Africa through the review of relevant literature.

    Method: We sourced for evidence through the following databases: PubMed, Science direct and Scopus from 30th November to 31st December 2019 as well as the reference list of the studies included. A total of 22 peer reviewed articles were included in the review (8065 respondents). Quality appraisal of the included studies was assessed using critical appraisal tools for cross-sectional studies.

    Result: Across the studies, diverse but high prevalence of WPV ranging from 9% to 100% was reported with the highest in South Africa (54%-100%) and Egypt (59.7%-86.1%). The common types were verbal, physical, sexual harassment and psychological violence. The correlates of WPV reported were gender, age, shift duty, emergency unit, psychiatric unit, nursing, marital status and others. Various impacts were reported including psychological impacts and desire to quit nursing. Patients and their relatives, the coworkers and supervisors were the mostly reported perpetrators of violence. Doctors were mostly implicated in the sexual violence against nurses. Policy on violence and management strategies were non-existent across the studies.

    Conclusion: High prevalence of WPV against healthcare workers exists in Africa but there is still paucity of research on the subject matter. However, urgent measures like policy formulation and others must be taken to address the WPV as to avert the impact on the healthcare system.

  3. Fulltext Docking based screening and molecular dynamics simulations to identify potential selective PDE4B inhibitor
    Al-Nema M, Gaurav A, Lee VS
    Heliyon, 2020 Sep;6(9):e04856.
    PMID: 32984588 DOI: 10.1016/j.heliyon.2020.e04856
    Inhibition of phosphodiesterase 4 (PDE4) is a promising therapeutic approach for the treatment of inflammatory pulmonary disorders, i.e. asthma and chronic obstructive pulmonary disease. However, the treatment with non-selective PDE4 inhibitors is associated with side effects such as nausea and vomiting. Among the subtypes of PDE4 inhibited by these inhibitors, PDE4B is expressed in immune, inflammatory and airway smooth muscle cells, whereas, PDE4D is expressed in the area postrema and nucleus of the solitary tract. Thus, PDE4D inhibition is responsible for the emetic response. In this regard, a selective PDE4B inhibitor is expected to be a potential drug candidate for the treatment of inflammatory pulmonary disorders. Therefore, a shared feature pharmacophore model was developed and used as a query for the virtual screening of Maybridge and SPECS databases. A number of filters were applied to ensure only compounds with drug-like properties were selected. Accordingly, nine compounds have been identified as final hits, where HTS04529 showed the highest affinity and selectivity for PDE4B over PDE4D in molecular docking. The docked complexes of HTS04529 with PDE4B and PDE4D were subjected to molecular dynamics simulations for 100ns to assess their binding stability. The results showed that HTS04529 was bound tightly to PDE4B and formed a more stable complex with it than with PDE4D.
  4. Evolution of adsorption process for manganese removal in water via agricultural waste adsorbents
    Rudi NN, Muhamad MS, Te Chuan L, Alipal J, Omar S, Hamidon N, et al.
    Heliyon, 2020 Sep;6(9):e05049.
    PMID: 33033772 DOI: 10.1016/j.heliyon.2020.e05049
    Manganese has recently been a topic of interest among researchers, particularly when 1,752 million tonnes of manganese are expected to be produced by the steel industry in 2020. Manganese discharges from industrial effluents have increased manganese contamination in water sources. Its concentrations of more than 0.2 mg/L in the water sources could have negative impacts on human health and the aquatic ecosystem. Thereby, the available water treatment processes face challenges in effectively removing manganese at low cost. In response to these challenges, adsorption has emerged as one of the most practical water treatment processes for manganese removal. In particular, agricultural waste adsorbents received a lot of attention owing to their low cost and high efficiency (99%) in the removal of manganese. Therefore, this paper reviews the removal of manganese by adsorption process using agricultural waste adsorbents. The factors affecting the adsorption process, the mechanisms, and the performances of the adsorbents are elucidated in detail.
  5. Fulltext Triple right testicular veins and their variant termination and communications
    Nayak SB, Kodimajalu Vasudeva S
    Heliyon, 2020 Sep;6(9):e05014.
    PMID: 32995649 DOI: 10.1016/j.heliyon.2020.e05014
    Testicular veins are known to show many variations in their origin, course and termination. Some of their variations can lead to male sterility. We report a unique variation of right testicular vein here. Pampiniform plexus reduced to three testicular veins (medial, middle and lateral) at the deep inguinal ring on the right side. The medial vein terminated into the right renal vein, the middle vein terminated into the inferior vena cava above the level of right renal vein (close to the suprarenal gland) and the lateral vein terminated partly into the veins in the capsules of the kidney and partly into the veins under the diaphragm. The medial and middle testicular veins were connected through an oblique communicating vein. The middle and lateral testicular veins were also connected to each other through another oblique communicating vein. Knowledge of this case could be useful to radiologists, nephrologists and surgeons in general.
  6. Techno-economic analysis of bio-briquette from cashew nut shell waste
    Ifa L, Yani S, Nurjannah N, Darnengsih D, Rusnaenah A, Mel M, et al.
    Heliyon, 2020 Sep;6(9):e05009.
    PMID: 33005808 DOI: 10.1016/j.heliyon.2020.e05009
    The implementation of this research consists of 2 (two) aspects: the making and testing of bio-briquettes called technological aspects and economic analysis called economic aspects. Bio-briquettes is made from cashew nutshell waste obtained from Southeast Sulawesi, Indonesia. It is followed by pyrolysis, which is carried out in a simple batch type reactor by heating using liquefied petroleum gas (LPG). The bio-briquettes product has a calorific value of 29.49 MJ/kg, moisture content of 5.3%, ash content of 4.96%, volatile substances content of 17.16%, and carbon content of 72.62%, which meets the universally accepted bio-briquettes standard (SNI 016235-2000), Japanese, English and ISO 17225. The bio-briquettes product is suitable as an energy source. The economic analysis of the cashew nutshell was analyzed to determine its economic feasibility. For the bio-briquettes production capacity in 2,000 tons/year, cashew nut shell-briquettes products can be sold at 1,052,878 USD/year. The total production cost is USD842,304/year. The net profit is of USD147,402/year. The cost of LPG for 2,000 tons/year production capacity is USD954,358/years. The replacement of LPG with cashew seed bio-briquettes tends to help the average household of Muna Regency community to reduce the annual cost by 37.00%. In conclusion, bio-briquettes production's economic feasibility as analyzed from the investment rate is 23.55%, payout time is 3.42 years, and break-even point is 50.09%.
  7. Rainwater chemistry of acid precipitation occurrences due to long-range transboundary haze pollution and prolonged drought events during southwest monsoon season: climate change driven
    Payus CM, Jikilim C, Sentian J
    Heliyon, 2020 Sep;6(9):e04997.
    PMID: 33005801 DOI: 10.1016/j.heliyon.2020.e04997
    The purposes of this research were to study the characteristics chemistry of pH, anions and cations in rainwater, and to identify the possible sources that contributing to the acid precipitation during southwest monsoon season with occurrence of extreme drought event. During the southwest monsoon season, it normally occurs along with haze phenomenon that every year will hit Southeast Asia. This condition will aggravate with high acidic particles in the atmosphere due to the prolonged drought. The analysed parameters which involved pH, anions (NO3-, SO42- and Cl-) and cations (Ca2+, Mg2+, Na+ and K+) were analysed using pH meter, Hach DR 2800, argentometric method and ICP-OES. From the findings, it showed that acid rain occurred during the southwest monsoon season with the range of pH values from 4.95 ± 0.13 to 6.40 ± 0.03 and the total average of pH 5.71 ± 0.32. Anions NO3-, SO42- and Cl- were found to be the dominant compositions of the acid rain occurrences with higher concentrations detected. In overall, rural area recorded with higher acidity of precipitation at total average of pH 5.54 ± 0.39 compared to urban area at pH 5.77 ± 0.26. Rural area surprisingly recorded higher frequency occurrences of acid rain with pH lesser than 5.6 and below compared to urban area. As for public health and safety, all rainwater samples during the acid rain event were found exceeded the allowable limits of NWQS and WHO standards, that shown not suitable for skin contact, recreational purposes even for drinking purposes.
  8. Secretion of pro-oncogenic AGR2 protein in cancer
    Moidu NA, A Rahman NS, Syafruddin SE, Low TY, Mohtar MA
    Heliyon, 2020 Sep;6(9):e05000.
    PMID: 33005802 DOI: 10.1016/j.heliyon.2020.e05000
    Anterior gradient-2 (AGR2) protein mediates the formation, breakage and isomerization of disulphide bonds during protein maturation in the endoplasmic reticulum (ER) and contributes to the homoeostasis of the secretory pathway. AGR2 promotes tumour development and metastasis and its elevated expression is almost completely restricted to malignant tumours. Interestingly, this supposedly ER-resident protein can be localised to other compartments of cancer cells and can also be secreted into the extracellular milieu. There are emerging evidences that describe the gain-of-function activities of the extracellular AGR2, particularly in cancer development. Here, we reviewed studies detailing the expression, pathological and physiological roles associated with AGR2 and compared the duality of localization, intracellular and extracellular, with special emphasis on the later. We also discussed the possible mechanisms of AGR2 secretion as well as deliberating the functional impacts of AGR2 in cancer settings. Last, we deliberate the current therapeutic strategies and posit the potential use AGR2, as a prognosis and diagnosis marker in cancer.
  9. Fulltext Development of novel microsatellite markers using RAD sequencing technology for diversity assessment of rambutan (Nephelium lappaceum L.) germplasm
    Ab Razak S, Mad Radzuan S, Mohamed N, Nor Azman NHE, Abd Majid AM, Ismail SN, et al.
    Heliyon, 2020 Sep;6(9):e05077.
    PMID: 33024864 DOI: 10.1016/j.heliyon.2020.e05077
    The trend of microsatellite marker discovery and development revolved as a result of the advancement of next generation sequencing (NGS) technology as it has developed numerous microsatellites within a short period of time at a low cost. This study generated microsatellite markers using RAD sequencing technologies for the understudied Nephelium lappaceum. A total of 1403 microsatellite markers were successfully designed, which consisted of 853 di-, 525 tri-, 17 tetra-, 5 penta-, and 3 hexanucleotide microsatellite markers. Subsequently, selection of 39 microsatellites was made for the evaluation of genetic diversity of the selected 22 rambutan varieties. Twelve microsatellites, which exhibited high call rates across the samples, were used to assess the diversity of the aforementioned rambutan varieties. The analysis of 12 microsatellites revealed the presence of 72 alleles and six alleles per locus in average. Furthermore, the polymorphic information content (PIC) value ranged from 0.326 (NlaSSR20) to 0.832 (NlaSSR32), which included an average of 0.629 per locus, while the generated Neighbour Joining dendrogram showed two major clusters. The pairwise genetic distance of shared alleles exhibited a range of values from 0.046 (R134↔R170) to 0.818 (R5↔R170), which suggested highest dissimilarity detected between R5 and R170. Notably, these research findings would useful for varietal identification, proper management and conservation of the genetic resources, and exploitation and utilization in future breeding programs.
  10. Fulltext Multi-audience tracking with RGB-D camera on digital signage
    Low CC, Ong LY, Koo VC, Leow MC
    Heliyon, 2020 Sep;6(9):e05107.
    PMID: 33024875 DOI: 10.1016/j.heliyon.2020.e05107
    Digital signage is widely utilized in digital-out-of-home (DOOH) advertising for marketing and business. Recently, the combination of the digital camera and digital signage enables the advertiser to gather the audience demographic for audience measurement. Audience measurement is useful for the advertiser to understand the audience's behavior and improve their business strategies. When an audience is facing the digital display, the vision-based DOOH system will process the audience's face and broadcast a personalized advertisement. Most of the digital signage is available in an uncontrolled environment of public areas. Thus, it poses two main challenges for the vision-based DOOH system to track the audience's movement, which are multiple adjacent faces and occlusion by passer-by. In this paper, a new framework is proposed to combine the digital signage with a depth camera for tracking multi-face in the three-dimensional (3D) environment. The proposed framework extracts the audience's face centroid position (x, y) and depth information (z) and plots into the aerial map to simulate the audience's movement that is corresponding to the real-world environment. The advertiser can further measure the advertising effectiveness through the audience's behavior.
  11. Fulltext Holistic approach to microwave-reflux extraction and thermo-analytical fingerprints of under-utilized Artocarpus heterophyllus seed wastes
    Olalere OA, Gan CY, Abdurahman HN, Adeyi O, Ahmad MM
    Heliyon, 2020 Aug;6(8):e04770.
    PMID: 32923719 DOI: 10.1016/j.heliyon.2020.e04770
    The increase in wastes generated from jackfruit seeds has been largely under-utilized in Malaysia. Due to the high nutritional and medicinal content embedded in the cellulosic structure of jackfruit wastes, a need then arises for their physicochemical elucidations. In this study, the extraction of Artocarpus heterophyllus seed was carefully investigated using Taguchi orthogonal optimization design. Complete functional group characteristics and chemical profile of the A. heterophyllus seed extracts were obtained using different physicochemical characterization. The optimal conditions of the microwave extraction parameters were determined at 5 min of irradiation time, 450 W of power and 50 °C of temperature. Under this condition, the optimal yield of 17.34 (mg/g) % was achieved at an SNR ratio of 24.78. The mass spectrometry analysis tentatively identified a total of 90 and 148 secondary metabolites at positive and negative ESI modes, respectively. The chemical profile obtained provided a baseline reference for further investigation on the food and medicinal bioactive from Artocarpus heterophyllus seed oleoresins. The FT-infrared emission spectrum shows the presence of some specific carbohydrates and amide protein functional groups directly linked to C-O (1008 cm-1) the carbonyl (C=O) groups, respectively. Moreover, the morphological characteristics of the jackfruit raw and crude extracts conspicuously revealed large-sized globules which suggest the carbohydrates and protein contents. The result of this study indicates that the use of microwave extraction technology produced high-quality extracts with lower degradation of the thermal labile constituents. This will assist in determining the suitable conditions necessary for the total recovery of medicinal and nutritional constituents and conversion of agricultural waste products into useful products.
  12. Fulltext Numerical study of tides in the Malacca Strait with a 3-D model
    Haditiar Y, Putri MR, Ismail N, Muchlisin ZA, Ikhwan M, Rizal S
    Heliyon, 2020 Sep;6(9):e04828.
    PMID: 32939416 DOI: 10.1016/j.heliyon.2020.e04828
    Malacca Strait (MS) has an important role and potential for many countries. It is a major transportation route for oil and commodities across continents. In addition, various activities such as shipping, fishing, aquaculture, oil drilling, and energy are also carried out in MS. Tides strongly affect the MS environment so that it becomes a major parameter in MS management. This paper is the first study, which presents MS tidal hydrodynamics based on a baroclinic and nonhydrostatic approach. Tidal hydrodynamics in MS and the surrounding waters were assessed using tidal forces, temperature, salinity, and density. This study analyzes the amplitude, phase, current ellipses, and semi-major axis of the tides. These variables are obtained from the simulation results of the three-dimensional numerical models of M2 tides and combined tides (M2, S2, N2, K1, and O1) with nonhydrostatic models. Then the results obtained are verified by observation data. Amplitude and phase of the tidal wave in MS originate from two directions, namely the northern part of MS (Andaman Sea) and the South China Sea (SCS). Tides from the north of MS propagate into the MS, while tides from the SCS travel to Singapore Waters (SW) and the south of MS. This causes a complex residual flow in SW and shoaling in the middle of MS. Shoaling in the middle of MS is characterized by a large amplitude and semi-major, as in B. Siapiapi. The results of this analysis show that tidal waves are dominated by semidiurnal types rather than diurnal types. The M2 current ellipse has dominantly anticlockwise rotation along the west of the MS, while along the east of MS, it has generally a clockwise rotation.
  13. Fulltext Growth and metal uptake of spinach with application of co-compost of cat manure and spent coffee ground
    Mohd Noor Keeflee SNK, Wan Mohd Zain WNA, Mohd Nor MN, Jamion NA, Yong SK
    Heliyon, 2020 Sep;6(9):e05086.
    PMID: 33015401 DOI: 10.1016/j.heliyon.2020.e05086
    Cat manure (CM) possesses high level of nutrients for growing food crop. However, animal manure may contain toxic elements that may contaminate food crop. Spent coffee ground (SCG) may be used to reduce mobility of heavy metals and reduce crop uptake. In this study, SCG was composted with CM for 31 days to produce a co-compost (SCG-CM) for growing spinach (Spinacia oleracea). The growth rate of spinach was assessed until its maturity, and the metal uptake of spinach shoot was determined thereafter using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The effect of soil treatment with SCG-CM on the height and elemental composition of spinach were compared with that of chicken manure compost (CMC). The prepared composts were primarily organic matter (72.9-81.4 % w/w) with the rest are ash (13.3-23.4 % w/w) and moisture (1.2-2.6 % w/w). Zinc content in SCG-CM (1261 ± 0.1 mg/kg) is significantly higher than that of soil and CMC (p < 0.05) and has exceeded the maximum permissible limit set by European Union Standard (2002) and the Malaysian Compost Quality Standard and Guidelines (2000). Matured spinach reached maximum plant height after 33 days. The amendment of SCG-CM significantly increased the height of spinach (32 ± 6 cm) compared to that of CMC (13 ± 1 cm) (p < 0.05). However, contents of Zn, Cu, Pb and Cd were not increased for spinach grown in the SCG-CM-amended soil, and the level of those elements are below permissible limit set by the Malaysian Food Act 1983 and Food Regulations 1985. This study shows that SCG-CM is effective in improving yield without causing accumulation of toxic trace elements in spinach.
  14. Fulltext Performance of geotextile-based slow sand filter media in removing total coli for drinking water treatment using system dynamics modelling
    Fitriani N, Kusuma MN, Wirjodirdjo B, Hadi W, Hermana J, Ni'matuzahroh, et al.
    Heliyon, 2020 Sep;6(9):e04967.
    PMID: 33015386 DOI: 10.1016/j.heliyon.2020.e04967
    In a slow sand filter, a biological layer consisting of alluvial mud and various types of microorganisms grows and attaches to the sand media and forms a matrix called schmutzdecke. Changes to several factors, including the quality of raw water, filtration speed, and the addition of media, affect the performance of the slow sand filter unit in producing treated water. Geotextiles can be equipped to improve the performance of a slow sand filter in removing pollutants. The selection of several factors that affect slow sand filter performance can be used as a starting point for the engineering system to determine the best pattern of performance behavior. This approach was carried out by looking at the dynamic behavior patterns of slow sand filter system performance in treating raw water. This research has not yet been conducted extensively. The dynamic behavior pattern approach to the performance of the slow sand filter unit was used to obtain the behavior model for the schmutzdecke layer on the filter. The system dynamic approach focused on treatment scenarios that can determine the behavior of the slow sand filter system. Several factors were assessed, including temperature, turbidity, nutrient concentration, algal concentration, bacteria and dissolved oxygen. Model simulation results show that the comparison of C: N: P values affected the performance of the schmutzdecke layer in removing total coli. The slow sand filter unit was capable of producing treated water with a total amount of coli equal to 0 on the C: N: P values of 85: 5.59: 1.25, respectively, and a 9 cm geotextile thickness.
  15. Fulltext Mode of delivery, order of birth, parental age gap and autism spectrum disorder among Malaysian children: A case-control study
    Andoy Galvan JA, Ramalingam PN, Patil SS, Bin Shobri MAS, Chinna K, Sahrir MS, et al.
    Heliyon, 2020 Oct;6(10):e05068.
    PMID: 33083595 DOI: 10.1016/j.heliyon.2020.e05068
    Rising prevalence of autism spectrum disorders (ASD) in the last decades has led research to focus on the diagnosis and identification of factors associated with ASD. This paper sought for possible factors that put children at risk for ASD. In this study, we investigated the association between ASD and parental ages, parental age gaps, birth order and birth delivery method in Malaysian population. In this school-based case control study, 465 children with ASD 464 controls participated. Questionnaires were distributed to the parents of the selected children through the respective principals. Among the tested variables, Caesarean section (OR = 1.63, 95% CI 1.20, 2.20), earlier order of birth in the family (OR = 0.68, 95% CI 0.59, 0.77) and increasing gap in parental ages (OR = 1.04, 95% CI 1.001, 1.07) were significantly associated with ASD. This study concludes that Caesarean section, earlier order of birth in the family and increasing gap in parental age are independent risk factors for developing autism among Malaysian children.
  16. Fulltext The mediating role of procedural justice on the relationship between job analysis and employee performance in Jordan Industrial Estates
    Khtatbeh MM, Mahomed ASB, Rahman SBA, Mohamed R
    Heliyon, 2020 Oct;6(10):e04973.
    PMID: 33083583 DOI: 10.1016/j.heliyon.2020.e04973
    Job analysis and employees' perception of justice have a significant influence on employee performance within an organization. This study examined the relationships between job analysis, job performance, and procedural justice among local employees in Jordan Industrial Estates. The literature demonstrated gaps in knowledge regarding the relationships between these variables in developing countries, which are intended to be filled by this study. The study drew from the pay model and equity theory. Data were collected with a survey questionnaire from 690 Jordanian employees working in three industrial estates. The data were analyzed through structural equation modelling (SEM) using SPSS and AMOS software tools. The results indicated to a significant positive relationship between job analysis and job performance, job analysis and procedural justice, and a positive relationship between procedural justice and job performance. Also, it is found that procedural justice mediates the relationship between job analysis and job performance. It is expected that the results of this study would have an impact on employee's performance through the fair implementation of one of the human resources practices, namely, job analysis, and thus organizational performance. Also, it contributes to the body of knowledge and supports the mediating role of procedural justice in decisions taken within the organization.
  17. Fulltext News consumption patterns on Twitter: fragmentation study on the online news media network
    Gaol FL, Maulana A, Matsuo T
    Heliyon, 2020 Oct;6(10):e05169.
    PMID: 33083617 DOI: 10.1016/j.heliyon.2020.e05169
    The development of news media and social media has radically changed the way the public consumes information. This study explores the structure of online news media networks in three countries, namely Indonesia, Malaysia and Singapore, to investigate the phenomenon of fragmentation in the news consumption pattern on social media. Based on the results of the three network indicators used in this study, it can be concluded that the structure of online news media networks in Indonesia and Malaysia shows a tendency of fragmentation. In contrast, this study did not find sufficient evidence that the phenomenon of fragmentation was occurring in the Singapore media network. In-depth analysis on each formed media cluster shows that online news media in Indonesia and Malaysia tend to group based on similarity in market segments, regions or political alignments.
  18. Fulltext In situ ophthalmic gel forming systems of poloxamer 407 and hydroxypropyl methyl cellulose mixtures for sustained ocular delivery of chloramphenicole: optimization study by factorial design
    Kurniawansyah IS, Rusdiana T, Sopyan I, Ramoko H, Wahab HA, Subarnas A
    Heliyon, 2020 Nov;6(11):e05365.
    PMID: 33251348 DOI: 10.1016/j.heliyon.2020.e05365
    Background: Conventional drug delivery systems have some major drawbacks such as low bioavailability, short residence time and rapid precorneal drainage. An in situ gel drug delivery system provides several benefits, such as prolonged pharmacological duration of action, simpler production techniques, and low cost of manufacturing. This research aims to get the optimum formula of chloramphenicol in situ gel based on the physical evaluation.

    Methods: The effects of independent variables (poloxamer 407 and hydroxypropyl methyl cellulose (HPMC) concentration) on various dependent variables (gelling capacity, pH and viscosity) were investigated by using 32 factorial design and organoleptic evaluation was done with descriptive analysis.

    Results: The optimized formula of chloramphenicol in situ gel yielded 9 variations of poloxamer 407 and HPMC bases composition in % w/v as follows, F1 (5; 0.45), F2 (7.5; 0.45), F3 (10; 0.45), F4 (5; 0.725), F5 (7.5; 0.725), F6 (10; 0.725), F7 (5; 1), F8 (7.5; 1), F9 (10; 1). The results indicated that the organoleptic, pH, and gelling capacity parameters matched all formulas (F1-F9), however, the viscosity parameter only matched F3, F6, F8, and F9. Based on factorial design, F6 had the best formula with desirability value of 0.54, but the design recommended that formula with the composition bases of poloxamer 407 and HPMC at the ratio of 8.16 % w/v and 0.77 % w/v, respectively, was the optimum formula with a desirability value of 0.69.

    Conclusion: All formulas have met the Indonesian pharmacopoeia requirements based on the physical evaluation, especially formula 6 (F6), which was supported by the result of factorial design analysis.

  19. Fulltext Microalgal metabolites as anti-cancer/anti-oxidant agents reduce cytotoxicity of elevated silver nanoparticle levels against non-cancerous vero cells
    Hussein HA, Maulidiani M, Abdullah MA
    Heliyon, 2020 Oct;6(10):e05263.
    PMID: 33102866 DOI: 10.1016/j.heliyon.2020.e05263
    Heavy metal pollution has become a major concern globally as it contaminates eco-system, water networks and as finely suspended particles in air. In this study, the effects of elevated silver nanoparticle (AgNPs) levels as a model system of heavy metals, in the presence of microalgal crude extracts (MCEs) at different ratios, were evaluated against the non-cancerous Vero cells, and the cancerous MCF-7 and 4T1 cells. The MCEs were developed from water (W) and ethanol (ETH) as green solvents. The AgNPs-MCEs-W at the 4:1 and 5:1 ratios (v/v) after 48 and 72 h treatment, respectively, showed the IC50 values of 83.17-95.49 and 70.79-91.20 μg/ml on Vero cells, 13.18-28.18 and 12.58-25.7 μg/ml on MCF-7; and 16.21-33.88 and 14.79-26.91 μg/ml on 4T1 cells. In comparison, the AgNPs-MCEs-ETH formulation achieved the IC50 values of 56.23-89.12 and 63.09-91.2 μg/ml on Vero cells, 10.47-19.95 and 13.48-26.61 μg/ml on MCF-7; 14.12-50.11 and 15.13-58.88 μg/ml on 4T1 cells, respectively. After 48 and 72 h treatment, the AgNPs-MCE-CHL at the 4:1 and 5:1 ratios exhibited the IC50 of 51.28-75.85 and 48.97-69.18 μg/ml on Vero cells, and higher cytotoxicity at 10.47-16.98 and 6.19-14.45 μg/ml against MCF-7 cells, and 15.84-31.62 and 12.58-24.54 μg/ml on 4T1 cells, respectively. The AgNPs-MCEs-W and ETH resulted in low apoptotic events in the Vero cells after 24 h, but very high early and late apoptotic events in the cancerous cells. The Liquid Chromatography-Mass Spectrometry-Electrospray Ionization (LC-MS-ESI) metabolite profiling of the MCEs exhibited 64 metabolites in negative ion and 56 metabolites in positive ion mode, belonging to different classes. The microalgal metabolites, principally the anti-oxidative components, could have reduced the toxicity of the AgNPs against Vero cells, whilst retaining the cytotoxicity against the cancerous cells.
  20. Fulltext Impact of prebiotics on equol production from soymilk isoflavones by two Bifidobacterium species
    Mustafa SE, Mustafa S, Ismail A, Abas F, Abd Manap MY, Ahmed Hamdi OA, et al.
    Heliyon, 2020 Oct;6(10):e05298.
    PMID: 33134584 DOI: 10.1016/j.heliyon.2020.e05298
    The influence of commercial prebiotics (fructo-oligosaccharides and inulin) and sugars (glucose and sucrose) on enhancing equol production from soymilk isoflavones by Bifidobacterium longum BB536 and Bifidobacterium breve ATCC 15700 was evaluated in vitro. Sterilized soymilk was inoculated with each bacterial species at 37 °C for 48 h. The growth and β-glucosidase enzyme activity for the two Bifidobacterium species in soymilk throughout fermentation were assessed. The highest viable count for B. breve (8.75 log CFU/ml) was reached at 36 h and for B. longum (8.55 log CFU/ml) at 24 h. Both bacterial species displayed β-glucosidase activity. B. breve showed increased enzyme activity (4.126 U) at 36 h, while B. longum exhibited maximum activity (3.935 U) at 24 h of fermentation. Among the prebiotics screened for their effect in isoflavones transformation to equol, inulin delivered the highest effect on equol production. The co-culture of B. longum BB536 and B. breve ATCC15700 in soymilk supplemented with inulin produced the highest level (11.49 mmol/l) of equol at 48 h of fermentation process. Level of daidzin declined whereas that of daidzein increased, and then gradually decreased due to formation of equol when soymilk was fermented using bifidobacterial. This suggests that the nutritional value of soymilk may be increased by increasing bioavailability of the bioactive ingredients. Collectively these data identify probiotics and prebiotic combinations suitable for inclusion in soymilk to enhance equol production.
Related Terms
    Try searching for something
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links